What nobby is saying is, since Jim Humble has misrepresented the bottle of sodium chlorite solution as something it's not (ie a miracle and a mineral) then he is a scammer, also he may have exaggerated it's benefits and understated it's potential harm at least initially and overpriced it to fund his supposed work in africa etc(not necessarily bad if he does such work)
Is it dangerous to use, yes if you use it carelessly but I highly doubt 15 drops could cause anyone lasting harm in any way but taking it 3 times a day for a long period could do so and that would depend on who was taking it
On the other hand there are better and safer alternatives for a lot of things some people use it for, so why many people use it at all is likely due to it's promotion as a harmless natural miracle supplement which it isnt. On the other hand Iodine is and would be a better choice since it seems to able to accomplish much of what Miracle-Mineral-Supplement claims to and more